Mateus De Freitas Virgilio Pereira (of Professor Cesnik and Professor Kolmanovsky groups) is defending his dissertation, "Constrained Control for Load Alleviation in Very Flexible Aircraft," on April 19th at 8:00 a.m. in person and via Zoom.

About the Defense
Motivated by the need for a greener aviation industry, aircraft designs are evolving toward higher aspect ratio wings to improve aerodynamic performance and reduce fuel consumption. Consequently, these vehicles are becoming increasingly flexible, thus more vulnerable to structural failure, especially when performing maneuvers or during encounters with gusts.

In this work, constrained control methods are investigated to design maneuver and gust load alleviation systems to keep the loads on these very flexible aircraft within safety limits. Two control architectures based on Model Predictive Control are proposed. Load alleviation is achieved by performing shape control of the flexible structure by imposing curvature constraints on critical stations on the wing and tail. For gust load alleviation, feedforward control is applied based on disturbance preview provided by LIDAR measurements. The control design for these large-scale systems is tackled by using model order reduction techniques and strategies to reduce the computational cost. In particular, it is shown that constraint aggregation methods can provide significant reductions in the computational footprint of Model Predictive Control.

The proposed load alleviation system is tested in a wind tunnel experiment. A half-aircraft model with a very flexible wing and free pitch is used to assess the performance of the controller in enforcing constraints on the vehicle while performing a longitudinal maneuver. Experimental results are presented to showcase the potential of the proposed system in addressing multiple objectives in load alleviation and its successful implementation in real time.